“The IRmadillo mid-infrared spectrometer is the most robust instrument that we have seen in the market for real time monitoring of ethanol fermentation. The spectrometer gives us better control of the fermentation process by providing real time information on how fermentation kinetics are progressing, in other words, how the sugars are being consumed and converted into ethanol”.
Julian Parra, Engineering and Technology Manager
The IRmadillo for Monitoring Bioethanol & Biofuel Processes
Bioethanol and biofuels productions are processes with natural and variable feedstocks, complex biochemical reactions, and at a potentially vast scale. Couple this with the fast turnaround time of each batch and the need to stick to the production schedule, and this makes analysing these processes in a cost effective and meaningful way a challenge. So how can plant operators obtain useful process metrics and analysis updates that enables them to control and optimise production?
The current approach is to take samples off-line and run them through an HPLC in the analysis lab. This can give high quality data, but is very slow, requires frequent recalibration of the HPLC itself, and normally only gives between 5 and 10 measurement points per batch. This lack of data makes it very hard to adjust the process, optimise it or even spot a problem early enough to take action. This is where the IRmadilloDiamond FTIR Spectrometer can change everything.
The Keit IRmadilloDiamond has been specifically designed to give high performance continuous measurements but will also withstand clean-in-place (CIP) protocols with no adverse effects. This enables real-time control, improved efficiency and therefore saves the plant money.
Bioethanol and Biofuel Fermentation and the IRmadillo
There are various subtle variations on bioethanol production processes, but in general they all include a milling step, liquefaction step, fermentation step and lastly a purification step. There are opportunities for improvement and cost savings at many of these steps, but the key recommended installation points for the IRmadillo are:
- Slurry tank
- Liquefaction tank
- Prop tank
- Fermentation tanks
- Ethanol line after drying
The process uses an enormous amount of water, which is recycled as much as possible to reduce cost. This allows the build up of contaminants and bacteria, which can ruin a batch if allowed to grow to too high a level. Also, the natural variation in feedstocks of corn, sorghum or other crops have different levels of sugars, which means differing amounts of yeast and enzyme are optimal depending on the time of year, source of feedstock and even the weather!
The IRmadillo helps with day-to-day monitoring of contaminants and problems (for example, spikes in glycerol readings indicating that the yeast is stressed), but it also enables better process control. If the plant operator sees that it’s regularly overdosing or underdosing yeast and enzyme – then this can be changed, and the effects observed immediately. This has a large impact on cost savings in the long run.
The IRmadillo can easily monitor the following chemicals and properties:
- Alcohols (Ethanol)
- Sugars (DP4+, DP3, DP2/Maltose, Glucose)
- Acids (Lactic, Acetic)
What about other “green” fuel types – like renewable diesel?
Different from bioethanol production, renewable diesel can be based on triglycerides, vegetable oils and animal fat feedstocks. Given the potentially variable nature of the feedstocks to this process, it is important to measure and understand the pre-treatment process to avoid potentially contaminating the reactor and catalyst bed. Replacing a catalyst bed can cost up to $1,000,000 as well as the opportunity cost of plant downtime, so detecting and removing contaminants before damage occurs is critical.
Furthermore, it is important to accurately record the inputs into the process to schedule preventative maintenance accordingly – for example, recording the total acid number (TAN) originating from free fatty acids in tallow or used cooking oils. The TAN can be directly linked to corrosion rates so measuring it in real time gives the plant the information it needs to decide whether to continue production or schedule in repairs.
The IRmadillo is ideally suited for the study of fats, fatty acids and other triglycerides. But it is also very good for monitoring phospholipids, phosphates, and other potential contaminants for renewable diesel pre-treatment. Traditional process FTIR spectrometers have not been robust enough for industrial use, and have fragile fibre optic elements. The IRmadillo is a static-optics FTIR spectrometer, designed for industrial installations. This makes it ideally suited for use in renewable diesel pre-treatment process monitoring and control.
What about other instruments – Raman, near infrared (NIR), & refractive index monitors?
- Raman spectroscopy is similar to the FTIR that drives the IRmadillo’s process monitoring, but it can be very strongly and negatively affected by particles and bubbles in the solution, as well as showing strong fluorescence in many cases.
- Near infrared (NIR) technologies provides much less specific information than FTIR – they’re very good in some industries, but not up to the demanding job of biofuel process monitoring.
- Refractive index monitors are cost effective instruments for simple systems, but they cannot cope with complicated mixtures such as those present in fermentation.
Raman, near infrared and refractive index monitors have been around for many years prior to the IRmadillo – put frankly, if they were the right tool wouldn’t you have one already?
Bioethanol and Biofuel FAQs
How do I use it? Do I need a PhD to calibrate it?
Not at all. Keit will work with you to either provide the instrument pre-calibrated as an analyser or we’ll calibrate it for you based on HPLC results – this depends on your process and will be confirmed at kick-off. Once it’s calibrated the calibration is stable, and can be expanded to multiple instruments in the same installation.
I tried IR before – it didn’t work!
It’s easy to confuse FTIR (mid-infrared) with FT-NIR (near infrared). There was a big push a few years ago in the industry to get near-infrared instruments (NIR) into plants. However, near infrared is very different to the mid-infrared light that the IRmadillo uses (FTIR).
FT-NIR instruments don’t actually look directly at the chemical bonds, but at “overtones”. This is a bit like trying to recognise someone from their shadow rather than looking at their face. It gives you a rough idea who it is, but to get full understanding you need the whole picture. For example, NIR will struggle to differentiate between DP4, DP3, DP2 and glucose, whereas FTIR can easily tell the difference.
How am I going to get this in to my plant then? What does installation look like?
The IRmadillo is designed to install directly into your process, and “fit it and forget” about it. It can be installed through an existing flange directly into the fermenters (either with or without a ball valve to isolate), and is equally suited for installation into recirculation pipework. The instrument can then communicate directly with your existing DCS or control system, becoming another part of the way you run your plant easily and simply.
The IRmadillo for Bioethanol and Biofuels
If you purchase the IRmadillo for bioethanol and biofuels processing you will receive:
- IRmadilloDiamond process analyser
- Interface and mounting accessories to integrate with your process (following a consultation with your engineering team)
- IRmadillo controller
- Calibration services
- Ongoing technical and recalibration support (as per your warranty or maintenance contract)
If you like the sound of this, please contact us for more information. We can arrange a trial installation on your plant for several months so you can see you yourself just what the IRmadillo can do.